Weigh beam and poise assembly



y 4, 1956 s. w. KAESER ETAL 2,756,042

WEIGH BEAM AND POISE ASSEMBLY Filed Jan. 11, 1955 2 Sheets-Sheet l IN VEN TORS SAMUEL M (4x652 Mae/c: S. 3580 61244 ALA ATTIC United States Patent WEIGH BEAM AND POISE ASSEMBLY Samuel W. Kaeser, Moline, and Maurice S. De Bo, East Moline, Ill., assignors to Fairbanks, Morse & Co., Clllcago, Ill., a corporation of Illinois Application January 11, 1955, Serial No. 481,103

Claims. (Cl. 265-565) This invention relates to weighing scales and particularly to improvements in the mounting of a movable poise on the weigh beam of a weighing scale.

In the construction of a beam scale provided with a poise, it is common practice .to mount the poise on the beam by means of rollers so that it may be moved readily and easily along the beam. In the use of rollers to facilitate movement of the poise, the heretofore known and prevailing arrangements of such rollers have resulted in undesirable poise rock and side play, which introduce binding and friction as the poise is moved along the beam. Also, and in addition to a releasable lever or handle for moving the poise along the beam, most poises are designed for type registering, in which case a handle and plunger arrangement is provided on the poise. In manipulation of the handles, particularly the latter, there is a tendency for the poise to rock about the beam, resulting in the first instance in binding between the poise and beam, and in the latter case incomplete or faulty type registering. These troublesome factors have been reduced to some extent by providing the poise with a multiplicity of rollers, or by precision machining the poise parts and roller mounts. However, the former method is ordinarily accompanied by an increase in friction, and the latter makes the poise diflicult and expensive to build.

Accordingly, to meet and overcome the above mentioned difficulty, it is most desirable and advantageous to provide a poise easily movable along the beam, yet so constructed and arranged in beam-mounted position as to prevent poise rock and side play.

It is, therefore, an important object of the present invention to provide in connection with a movable poise for use on the weigh beam of a weighing scale, an improved poise mounting arrangement permitting ready poise movement along the weigh beam with-out poise rock or side play relative to the beam.

Another object is the provision of a poise mounted on rollers movable along a track formed on the upper surface of the weigh beam, and having a guide roller which moves in a channel formed in the bottom surface of the weigh beam.

A further object of the invention is to provide an improved poise mounting on a scale weigh-beam, wherein the poise is in suspension on the beam through a pair of rollers carried by the poise and engaging a; beam track or rail having a rounded or larcuate roller-engaging surface, the rollers each being circumferentially grooved or channeled to present an arcuate rail-engaging surface complemental to the arcuate surface of the rail.

According to the general features of the present invention, the scale beam of the weighing scale is formed to provide a track of arcuate cross-section on the upper surface of said beam. The'poise, disposed on the beam, has two rollers journalled thereon and which are circumferentially grooved in such a manner as to engage the curved or arcuate surface of the track in close rolling contact therewith. The poise is ofiset to have a portion thereof disposed under the bottom surface of the 2,756,042 Patented July 24, 1956 beam, and a stub shaft extending vertically from the poise portion, carries a ball-bearing guide roller which is confined within a channel provided in the under surface of the beam. Thus, the poise is suspended from the beam by two rollers which eliminate poise side play by virtue of their arcuate track engaging surfaces in rail engagement, while the single guide roller serves in cooperation with the poise suspension rollers, to prevent poise rock relative to the beam.

Further objects, features, and advantages of this invention will appear or be apparent to one skilled in the art from the following description, reference being made to the accompanying drawings, in which:

Fig. 1 is a front elevational view of a scale beam and type registering poise constructed according to the teaching of the present invention.

Fig. 2 is an enlarged vertical sectional view taken on line 22 of Fig. 1.

Fig. 3 is a fragmentary sectional view taken substantially on line 33 of Fig. 2, with certain parts in elevation and some portions broken away.

Fig. 4 is an enlarged fragmentary cross-sectional view of the mounting for the bottom roller, showing the roller in engagement with the side walls of a longitudinal channel formed in the weigh beam.

Referring now to the drawings, the reference numeral 10 indicates a main scale beam, provided with a fulcrum pivot 11 supported by a bearing 12 mounted in a stand 14, and having a poise 15 disposed on said beam. The beam at one side of the pivot 11, is provided with a loop 16 to which the rod (not shown) connecting the beam with the scale platform mechanism (not shown) is connected, while its opposite end or tip is passed through a trig-stand 18.

As shown in Fig. 2, the upper portion 19 of beam 10 is formed to provide a track or rail 20 of arcuate crosssection presenting an arcuate rail surface 21, and a ridge or upstanding portion 22 having notches 23 cut therein. The beam is inclined outwardly, as at 24, and then vertically downward, as at 26, so that the lower portion 27 of the beam is offset considerably from the upper portion 19. The inclined portion 24 of the beam is provided with a scale 28 having graduations of large denomination, and the notches 23 of the ridge 22 correspond with these graduations (Fig. 3). The lower portion 27 of the beam is formed with a channel or groove 30 extending horizontally in the undersurface thereof, and having opposite parallel side walls 31.

As best seen in Fig. 2, the poise 15 comprises a top member 32, a back member 33, and a front member 34, which in assembly, as shown, affords a unitary structure disposed on the beam 10 in embracing relation thereto. The back member 33 simulates a reverse letter L, having a vertical portion 36 extending upwardly beyond the upper portion 19 of the beam, and a horizontal portion 37 extending beyond the vertical portion 26 of said beam.

The top member 32 is secured to the vertical portion 36 of the back member, as by bolts 38, and is formed so as to cooperate with said vertical portion to provide an irregular chamber or space 40 therebetween (Fig. 2), said space being positioned immediately above and in alignment with the beam track 20 and beam ridge 22 (Fig. 2). Two rollers 41 and 42 disposed in the space 40 and suitably journalled, as by axles 44 and 45, respectively, to the poise 15, each have a circumferential groove or channel providing a concave or arcuate surface which is in rolling contact with the arcuate beam track 20. For example and as shown in Fig. 2, roller 41 carried by axle 44 is provided with an arcuate rolling surface 46 which conforms to the surface 21 of track 20. It is apparent that such arcuate mating surfaces will maintain the rolling surfaces in close contact and prevent the rollers, and hence the poise, from moving sidewise relative to the beam track.

Also disposed within the space 40 is a latch member 48, adapted to engage the notches 23 formed in the beam ridge 22 (Fig. 3). Said latch member is pivo-tally secured to the poise, as by pin 49, and is urged into a notch engaging position by leaf spring mounted on the poise by screw 52. A handle portion 53,- formed on the latch member, projects through a passage 54 formed in the poise member and occupies a position suit able for easy hand operation. As seen in Fig. 3, depressing handle 53 will pivot the latch member 48 out of the notch engaging position shown, and permit movement of the poise 15 along the beam 10. When the poise is properly positioned for counterbalancing, releasing the handle will permit spring 50 to urge the latch back into notch engagement.

' The poise structure further includes an auxiliary poise device generally indicated at 56, and a graduated scale 57 for the latter, provided to indicate fractional parts of the weights determined by the scale. Additionally, there is provided a plunger mechanism 58 operated by actuating handle device 59 and effective in cooperation with weight-numeral bearing platens 60 and 61, for type registering scale weights on suitable print tickets or the like (not shown). These parts in detail and operation, may be in accordance with well-known constructions thereof, and hence need not be further described.

In manual operation of the handles 53 and 59, particularly the latter, forces may be thereby imposed on the poise tending to produce rocking thereof on the weigh beam. Such result is precluded in a positive manner, by thev presently improved poise mounting arrangement, including the anti-rocking provision now to be described.

Referring once again to Figs. 2 and 3, the front member 34 is secured to the horizontal portion 37 of back member 33 by bolts 62, said horizontal portion having a recessed portion 64 sufiicient to house suitable structure for supporting the plunger 58 and its associated parts. The. recessed portion 64 is also formed to provide a vertical groove or slot 65, said slot being disposed immediately below the channel 36 formed in the undersurface of beam. 10. A block 66 positioned in said slot and secured therein by bolt 68, has a stub shaft 69 extending vertically therefrom which carries an anti-friction bearing member or roller '70, said roller being of the ball bearing type, comprising an inner race 71 secured to shaft 69 by the wedging cooperation of shaft shoulder 72 and shaft head 73, an outer race '75, and a plurality of balls 76 disposed between the races. The roller is. disposed within the beam channel 30 and is of a size such that the outer race 75 is in close contact with the side surfaces 31 of said channel. It is apparent that the roller 74) closely engaged in the beam channel 30, will prevent the poise from rocking about its points of beam suspension provided by the rollers 41 and 42.

It should be noted, that the roller 70 is designed to maintain close contact with the channel side walls 31 during any poise movement, and consequently a sliding contact rather than a rolling contact is the normal action therebetween. However, should the channel be imperfect so that the roller cannot maintain a proper sliding contact With both side walls, then the roller Will be permitted to roll along that wall to which the. external forces on the poise. tend to. move it. It should be understood that the use of a vertical roller such as that described to facilitate poise movement when the channel is slightly imperfect, is, in no Wise conducive to developing poise rock; rather it compensates for very minor imperfections in a machined channel, and overcomes the necessity for pre cision machining the channel side walls. Thus, the poise is permitted to move smoothly along the beam and the change, if any, from a sliding contact to a rolling contact, and vice versa, isimperceptible. V

The improvedv poise mounting :as shown and described,

is simple in construction and provides exceptional poise stability against side play and rocking on the beam. Since the poise is suspended by two rollers 41 and 42 relatively spaced as shown, there can be no longitudinal rock or play of the poise relative to the beam. Also, because the rollers are formed to provide. arcuate rolling surfaces which ride on a mating arcuate track surface, side or lateral play of the poise relative to the beam is eliminated. Moreover and importantly to the present invention, the third roller 70 in the form of an anti-friction roller hearing, h ving a vertical axis and riding in a channel formed in the undersurface of the beam, provides the means for preventing any side rock of the poise about the beam, and particularly such side rock as otherwise occur in poise movement along the beam or through manual operation of the handle 59 in type registering weights. It is obvious that the roller 70 does not support nor carry any of the weight of the poise, but serves solely in cooperation with the suspension rollers 41 and 42, to constrain the poise in a positive manner, against any lateral movement whatsoever.

While the foregoing specification sets forth the pres ent invention in specific terms, it is to be understood that variations and modifications may be resorted to Without departing from the broad aspects of the invention as defined by the following claims.

Having now described the invention, what is claimed is:

1. In a scale, in combination, a weigh beam having a poise track formed on its upper surface, the lower portion of said beam being off-set with respect to said track, a channel formed in said lower portion and opening downwardly, a poise disposed about said beam, rollers mounted on the poise and movable upon the 'weigh beam track, and a roller mounted on the poise on a vertical axis and disposed within said channel.

2. In a scale, in combination, a weigh beam having a poise track presenting a convex arcuate rail surface, formed on its upper surface, the lower portion of said beam being off-set with respect to said track, a channel formed in the undersurface of said lower portion and opening downwardly, a poise disposed about said beam, rollers mounted on the poise each on a horizontal axis, and having rolling surfaces of concave arcuate form for rolling engagement with said convex arcuate rail surface of the track, and a roller mounted on the poise on a vertical axis, disposed within said channel.

3. A weigh beam and poise assembly for a Weighing scale, comprising a weigh beam having a track rail extending therealong and providing a channel in the under side of the beam, extending therein in parallel relation to the track rail, said channel providing opposite, parallel side walls, a poise member, roller means carried by the poise member and engaging said track rail in support of the poise member for movement along the weigh beam, and a roller device supported on the poise member and in contact with the opposite, parallel side walls of said channel.

4. A weigh 'beam and poise assembly as defined in claim 3, wherein the said roller device comprises an anti-friction bearing member having concentric race elements, the outer race element of which is in contact with the opposite, parallel side walls of said channel.

5; In a scale, in combination, a weigh beam having a track rail extending therealong and presenting a convex arcuate rail surface, formed on its upper surface, the lower portion of said beam being off-set with respect to said track, a channel formed in the undersurface of said lower portion, extendingtherein in parallel relation tothe track rail and opening downwardly, said channel providing opposite, parallel side walls, a poise member disposed about said beam, two rollers mounted on the poise member each on a horizontal axis, and having rolling surfaces of concave arcuate form for rolling 5 engagement with said convex areuate rail surface of the track, in support of the poise member for movement along the Weigh beam, and a third roller mounted on the poise 011a vertical axis, disposed within said channel, said 1 &3 i 1909 roller comprising an anti-friction bearing member hav- 5 1:157:716 Oct. 1ng co1 1ce ntr1c race elements, the outer race element of 1,587,630 Church June 8 WhlCh 18 in contact With the OPPOSltC, parallel side walls of sajdchanneL FOREIGN PATENTS 14,749 Great Britain 470,600 Canada Ian. 2,

6 References Cited in the file of this patent UNITED STATES PATENTS 

